SHORT COMMUNICATION Antifungal activity of the pygidial gland secretion of Laemostenus punctatus (Coleoptera: Carabidae) against cave-dwelling micromycetes Marija Nenadić 1 & Milica Ljaljević-Grbić 2 & Miloš Stupar 2 & Jelena Vukojević 2 & Ana Ćirić 3 & Vele Tešević 4 & Ljubodrag Vujisić 4 & Marina Todosijević 4 & Nikola Vesović 1 & Nemanja Živković 1 & Srećko Ćurčić 1 Received: 29 March 2017 /Revised: 22 May 2017 /Accepted: 23 May 2017 # Springer-Verlag Berlin Heidelberg 2017 Abstract The antifungal potential of the pygidial gland se- cretion of the troglophilic ground beetle Laemostenus punctatus from a cave in Southeastern Serbia against cave- dwelling micromycetes, isolated from the same habitat, has been investigated. Eleven collected samples were analyzed and 32 isolates of cave-dwelling fungi were documented. A total of 14 fungal species were identified as members of the genera Aspergillus, Penicillium, Alternaria, Cladosporium, Rhizopus , Trichoderma , Arthrinium, Aureobasidium, Epicoccum, Talaromyces, and Fusarium. Five isolates were selected for testing the antifungal activity of the pygidial gland secretion: Talaromyces duclauxi , Aspergillus brunneouniseriatus, Penicillium sp., Rhizopus stolonifer, and Trichoderma viride. The microdilution method has been ap- plied to detect minimal inhibitory concentrations (MICs) and minimal fungicidal concentrations (MFCs). The most sensi- tive isolate was Penicillium sp., while the other isolates dem- onstrated a high level of resistance to the tested agent. L. punctatus has developed a special mechanism of producing specific compounds that act synergistically within the secretion mixture, which are responsible for the antifungal action against pathogens from the cave. The results open op- portunities for further research in the field of ground beetle defense against pathogens, which could have an important application in human medicine, in addition to the environmen- tal impact, primarily. Keywords Laemostenus punctatus . Troglophilic ground beetle . Pygidial gland secretion . Cave-dwelling micromycetes . Antifungal activity Introduction Insects and fungi represent extremely differentiated groups of eukaryotes which could achieve very close communica- tion in various mutual biotopes (including caves) and inter- action at different trophic levels. Particularly, the interactions between insects and basidiomycetes, as well as entomo- pathogenic fungi, respectively, have been frequently studied (Selitskaya et al. 2014). In general, fungi-insect relationships are best studied in cave habitats. Therefore, it is certain that in cave biocoenoses micromycetes occupy a particular place. Of the fungal lower taxa (species and genera) reported from caves and mines, 69.1% are Ascomycota, 20% Basidiomycota, 6.6% Zygomycota, 2.6% Mycetozoa, 1% Oomycota, and 0.7% others (Vanderwolf et al. 2013). Fungi could occur in various substrates in caves such as cave sediments, rocks, vermiculations, soil, guano, decaying organic material, external/internal walls, dripping water, and underground rivers and lakes (Martin-Sanchez et al. 2012). In general, aerial microbiota are particularly scant due to excessive humidity. In addition to the role of composers and producers of mycotoxins, most cave-dwelling fungi Communicated by: Sven Thatje * Srećko Ćurčić srecko@bio.bg.ac.rs 1 Institute of Zoology, Faculty of Biology, University of Belgrade, Studentski Trg 16, 11000 Belgrade, Serbia 2 Institute of Botany and Botanical Garden BJevremovac^, Faculty of Biology, University of Belgrade, Takovska 43, 11000 Belgrade, Serbia 3 Institute for Biological Research BSiniša Stanković^, University of Belgrade, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia 4 Faculty of Chemistry, University of Belgrade, Studentski Trg 12–16, 11000 Belgrade, Serbia Sci Nat (2017) 104:52 DOI 10.1007/s00114-017-1474-4